Space Shuttle - Challenger Disaster

On January 28, 1986, Challenger and its crew were destroyed shortly after launch. The failure of an O-ring seal of a joint on one of the SRBs was the primary cause of the Challenger loss. SRBs are constructed in four cylindrical sections that must be sealed together completely to prevent the escape of the intensely hot byproducts of the burning fuel during launch. O-rings are rubber rings that play a crucial part in ensuring the seal.







The cold weather on the launch day made the rubber of an O-ring on the joint between the bottom two segments of the right SRB brittle, which, combined with the faulty design of the joint, allowed hot gases from the burning solid rocket fuel to escape. The gases and flames burned through the metal holding the rocket in position. When the rocket broke loose, it ruptured the side of the external fuel tank, allowing the liquid hydrogen and oxygen to mix prematurely and explode.

In early February 1986, as the nation mourned the tragic loss of the seven Challenger crew members, U.S. President Ronald Reagan announced the creation of the Presidential Commission on the Space Shuttle Challenger Accident. Chaired by William P. Rogers, former secretary of state, it became known as the Rogers Commission. NASA's Challenger Data and Design Analysis Task Force also was established at this time to support the work of the Rogers Commission.




More than 6,000 people were involved in the commission's four-month investigation of the accident, and some 15,000 transcript pages were taken during public and closed hearings. The commission's report was published and delivered to the president on June 6, 1986. Its recommendations included modifications of hardware and NASA procedures.

During the period when the space shuttle fleet was grounded, hundreds of major and minor modifications (many of which were planned before the accident) were incorporated into the shuttle system. The SRBs were completely redesigned, and a new joint design passed stringent examination and review.



The main space shuttle engines underwent the most aggressive ground-testing program in their history, equivalent in operational time to more than 36 missions. All engine improvements were certified to demonstrate improved reliability and operating safety margins, and they were incorporated into the engines used on the Discovery, Columbia, Atlantis, and Endeavour orbiters.

NASA safety programs were completely reorganized as a result of another Rogers Commission recommendation. The Office of Safety, Reliability, Maintainability, and Quality Assurance was established in 1986, and it now has direct authority for safety and related quality controls for all NASA operations. Today, more people are assigned to safety and related programs, improved communications have been initiated, and the review system for compliance to new procedures is rigorous and well-defined. The new Office of Safety ensures that the highest levels of NASA's management team are aware of safety issues.